There is known a substrate processing apparatus for performing processing on a substrate loaded into a processing chamber that can be evacuated by a vacuum pump such as a cryo pump or the like. In such a substrate processing apparatus, a desired vacuum level may not be obtained even if a pressure in the processing chamber is decreased by the vacuum pump due to a decrease in evacuation performance of the vacuum pump, the effect of impurities adsorbed onto an inner surface of the processing chamber, or the like.
Therefore, there is conventionally known, as a method of improving a vacuum level in a processing chamber, a method of providing a cooling panel and a getter pump as an auxiliary pump, in addition to a conventional vacuum pump, in a processing chamber (see, e.g., Japanese Patent Application Publication No. H6-306601) or a method of baking a processing chamber.
However, in the method of adding the auxiliary pump, a downtime is increased due to set-up or modification of a device which is required to add the auxiliary pump. Further, in the method of baking the processing chamber, a long period of time is required to improve a vacuum level in the processing chamber.